java.lang.RuntimeException: Can't create handler inside thread that has not called Looper.prepare()

While compiling am getting java.lang.RuntimeException: Can't create handler inside thread that has not called Looper.prepare()error.I googled it many times but still cant find a solution. Kindly help me with code.

SoapObject request = new SoapObject(NAMESPACE,
                            METHOD_GET_LOGIN_DETAILS);
                    SoapSerializationEnvelope envelope = new SoapSerializationEnvelope(
                            SoapEnvelope.VER11);
                    request.addProperty("loginUsr", user);
                    request.addProperty("loginPasswd", pass);
                    envelope.dotNet = true;// to handle .net services asmx/aspx
                    envelope.setOutputSoapObject(request);
                    HttpTransportSE ht = new HttpTransportSE(URL_PROTOCOL
                            + mSettings.getMmpServerpath() + URL_SERVICE_NAME);
                    ht.debug = true;
                    String soap_action = NAMESPACE + METHOD_GET_LOGIN_DETAILS;
                    ht.call(soap_action, envelope);
                    SoapPrimitive resultString = (SoapPrimitive) envelope
                            .getResponse();
                    File mImpOutputFile = Supporter.getImpOutputFilePathByCompany(
                            "MobManufacturingProcess", "00", "FiGoodsDetails"
                                    + ".xml");
                    if (!mImpOutputFile.exists()) {
                        Supporter.createFile(mImpOutputFile);
                    } else {
                        mImpOutputFile.delete(); // to refresh the file
                        Supporter.createFile(mImpOutputFile);
                    }

                    BufferedWriter buf = new BufferedWriter(new FileWriter(
                            mImpOutputFile, true));

                    buf.append("<" + "Details" + ">");

                    buf.append(resultString.toString());

                    buf.append("</" + "Details" + ">");
                    result = "success";

                    buf.close();


                } catch (SocketTimeoutException e) {
                    result = "time out error";
                    e.printStackTrace();
                } catch (IOException e) {
                    result = "input error";
                    e.printStackTrace();
                } catch (XmlPullParserException e) {
                    result = "error";
                    e.printStackTrace();
                } catch (Exception e) {
                    Log.e("tag", "error", e);
                    result = "error";
                }
                new DataLoadToDBOperation().execute();
                return result;  

            }
            @Override
            protected void onPostExecute(String result) {
                // TODO Auto-generated method stub
                /*String[] result=totVal.get(totVal.size());*/
                //super.onPostExecute(totVal);


                if (result.equals("success")) {
                    new DataLoadToDBOperation().execute();


                } else {
                    mToastMsg.showToast(LogInActivity.this,
                            "Invalid Username or Password");
                }


                dialog.cancel();
            }

        }

        private class DataLoadToDBOperation extends
                AsyncTask<String, String, String> {
            private String user;
            private String pass;
            private ProgressDialog dialog;

            public DataLoadToDBOperation() {
                dialog = new ProgressDialog(LogInActivity.this);
                dialog.setCancelable(false);
            }

            @Override
            protected String doInBackground(String... params) {

        String errMsg = "";

        try {

            String result = "";

            DataLoader fileLoader = new DataLoader(LogInActivity.this, mDBHelper,
                    user);

            List<String> importFileList = mSupporter.loadImportFileList();

            int totImpFile = importFileList.size();

            File salPer_folder_path = Supporter
                    .getImportFolderPath(user);

            List<String> compList = mSupporter
                    .getFolderNames(salPer_folder_path);

            int compSize = compList.size();

            if (compSize != 0) {

                startDBTransaction("db data loading"); // to start db
                                                        // transaction

                for (int c = 0; c < compList.size(); c++) {

                    String serCompName = compList.get(c);

                    for (int i = 0; i < totImpFile; i++) {

                        String fileName = importFileList.get(i);

                        if ((c > 0) && (fileName.equals("FigoodsDetail"))) {// to
                                                                        // load
                                                                        // FigoodsDetail
                                                                        // data
                                                                        // once
                            continue; // to continue for other files
                        }

                        mImpOutputFile = Supporter
                                .getImpOutputFilePathByCompany(spCode,
                                        serCompName, fileName + ".xml");

                        if (mImpOutputFile.exists()) {
                            InputStream inputStream;

                            inputStream = new FileInputStream(
                                    mImpOutputFile);
                            String[] resultArray = fileLoader
                                    .parseDocument(inputStream);

                            result = resultArray[0];
                            errMsg = resultArray[1];

                            if (!result.equals("success")) {
                                mDBHelper.mEndTransaction();
                                break;
                            }

                        } else {
                            result = "File not available";
                            mDBHelper.mEndTransaction();
                            break;
                        }

                    }

                    if (!result.equals("success")) { // to break from
                                                        // executing other
                                                        // companies
                        break;
                    }

                }
                endDBTransaction(); // to end db transaction

            } else {
                result = "File not available";
            }

            return result;
        } catch (Exception exe) {
            exe.printStackTrace();
            String errorCode = "Err-CLS-2";
            LogFileCreator.appendLog(errorCode + " : " + exe.getMessage()
                    + "\n" + errMsg);
            String result = "error";
            return result;
        }
    }

            /*@Override
            protected void onPostExecute(final String result) {
                if (dialog != null) {
                    if (dialog.isShowing()) {
                        dialog.dismiss();
                    }
                }

                if (result.equals("success")) {

                    mCmpnyNameList = loadListOfCompany();

                    mAdptSpnCompany = new ArrayAdapter<String>(LogInActivity.this,
                            android.R.layout.simple_dropdown_item_1line,
                            mCmpnyNameList);

                    mSpnCompany.setAdapter(mAdptSpnCompany);

                    // to delete file after loaded to db
                    mSupporter.deleteFileFolder(user);

                    mSupporter.navigateTo(MainMenu.class);

                } else if (result.equals("nosd")) {
                    mToastMsg.showToast(LogInActivity.this, "Sd card required");
                } else if (result.equals("parsing error")) {
                    mToastMsg
                            .showToast(LogInActivity.this, "Error during parsing the data");
                } else if (result.equals("File not available")) {
                    mToastMsg.showToast(LogInActivity.this, "File not available");
                } else {
                    mToastMsg.showToast(LogInActivity.this, "Errorrrrrrrrr");
                }

            }*/

            @Override
            protected void onPreExecute() {
                this.dialog.setMessage("Please wait until the data is loaded");
                this.dialog.show();
            }

            @Override
            protected void onProgressUpdate(String... values) {
            }
        }